Spam protection

General

Use SPF

Select to enable spam protection using SPF.

Check host in the HELO command

Turn on this option if you want hMailServer to check the host name that clients has specified in the HELO command. According to the SMTP specification, the host given in the HELO command should match the IP of the client.

Check that sender has DNS-MX records

If you enable this option, hMailServer will check that the senders domain has valid MX records in the DNS. If not, hMailServer will treat the message as spam.

When spam have been detected...

Use these settings to define what you want hMailServer to do when spam has been detected. The default behaviour is that hMailServer deletes the message, but it's possible to modify message headers instead.

Add X-hMailServer-Reason - When enabled, hMailServer will add a message header which contains information on why hMailServer considered the email to be spam.

Add to message subject - Using this setting, you can specify a text that hMailServer should prepend to the message subject. In combination with rules, spam messages can be moved to specific IMAP folders.

Tarpitting

Tarpitting is an antispam technique that works by slowing down the communication with spammers.